Commit graph

17 commits

Author SHA1 Message Date
Richard Newman
1817ce7c0b Performance and cleanup. r=emily
* Use fixed-size arrays for bootstrap datoms, not vecs.
* Wide-ranging cleanup.

    This commit:
    - Deletes some dead code.
    - Marks some functions only used by tests as cfg(test).
    - Adds pub(crate) to a bunch of functions.
    - Cleans up a few other nits.
2018-03-06 09:03:00 -08:00
Richard Newman
3d28949add Describe the default core schema, v1 (:db.schema/core). r=nalexander 2018-01-23 08:51:58 -08:00
Richard Newman
95b9c7f7f5
Atomic multi-tx (#489). r=emily,nalexander
* Pre: rename begin_transaction to begin_tx_application.

* Take an EXCLUSIVE transaction when bootstrapping, and an IMMEDIATE transaction when writing.

This avoids the remote possibility of another write sneaking in the door
while we're preparing to write, avoids us needing to upgrade locks, etc.

  After a BEGIN IMMEDIATE, no other database connection will be able to write
  to the database or do a BEGIN IMMEDIATE or BEGIN EXCLUSIVE. Other processes
  can continue to read from the database, however.

  An exclusive transaction causes EXCLUSIVE locks to be acquired on all
  databases. After a BEGIN EXCLUSIVE, no other database connection except for
  read_uncommitted connections will be able to read the database and no other
  connection without exception will be able to write the database until the
  transaction is complete.

* Hacky implementation of atomic multi-tx.

* Hold the last report, returning the InProgress from each operation.

* Rewrite transact in terms of InProgress.

* Test rollback.

* Remove unused imports.

* Don't use Rc for transaction reports.

* Pre: break out USER0 as a part boundary constant.

* Export TX0 and USER0 from mentat_db. This is for testing.

* Review comments: commenting.

* Test tempid allocation and rollback.
2017-12-05 07:58:24 -08:00
Nick Alexander
d1ac752de6 Parse without copying; parse keyword maps using macros.
This is a big commit, but it breaks into two conceptual pieces.  The
first is to "parse without copying".  We replace a stream of an owned
collection of edn::ValueAndSpan and instead have a stream of a
borrowed collection of &edn::ValueAndSpan references.  (Generally,
this is represented as an iterator over a slice, but it can be over
other things too.)  Cloning such iterators is constant time, which
improves on cloning an owned collection of edn::ValueAndSpan, which is
linear time in the length of the collection and additional time
depending on the complexity of the EDN values.

The second conceptual piece is to parse keyword maps using a special
parser and a macro to build the parser implementations.  Before, we
created a new edn::ValueAndSpan::Map to represent a keyword map in
vector form; since we're working with &edn::ValueAndSpan references
now, we can't create an &edn::ValueAndSpan reference with an
appropriate lifetime.  Therefore we generalize the concept of
iteration slightly and turn keyword maps in map form into linear
iterators by flattening the value maps.  This is a potentially
obscuring transformation, so we have to take care to protect against
some failure cases.  (See the comments and the tests in the code.)

After these changes, parsing using `combine` is linear time (and
reasonably fast).
2017-05-18 10:17:13 -07:00
Richard Newman
daca8def57 UUIDs and instants. Fixes #44, #45, #426, #427. (#438) r=nalexander
* Pre: unused import in translate.rs.

* Part 2: take a dependency on rusqlite for query arguments.

* Part 1: flatten V2 schema into V1. Add UUID and URI.

Bump expected ident and bootstrap datom count in tests.

* Part 5: parse edn::Value::Uuid.

* Part 3: extend ValueType and TypedValue to include Uuid.

* Part 4: add Uuid to query arguments.

* Part 6: extend db to support Uuid.

* Part 8: add a tx-parser test for #f NaN and #uuid.

* Part 7: parse and algebrize UUIDs in queries.

* Part 1: parse #inst in EDN and throughout query engine.

* Part 3: handle instants in db.

* Part 2: instants never matches integers in queries.

* Part 4: use DateTime for tx_instants.

* Add a test for adding and querying UUIDs and instants.

* Review comments.
2017-04-28 20:11:55 -07:00
Nick Alexander
5369f03464 Improve parsing of nested edn::ValueAndSpan streams. r=rnewman (#393)
* Pre: Expose more in edn.

* Pre: Make it easier to work with ValueAndSpan.

with_spans() is a temporary hack, needed only because I don't care to
parse the bootstrap assertions from text right now.

* Part 1a: Add `value_and_span` for parsing nested `edn::ValueAndSpan` instances.

I wasn't able to abstract over `edn::Value` and `edn::ValueAndSpan`;
there are multiple obstacles.  I chose to roll with
`edn::ValueAndSpan` since it exposes the additional span information
that we will want to form good error messages in the future.

* Part 1b: Add keyword_map() parsing an `edn::Value::Vector` into an `edn::Value::map`.

* Part 1c: Add `Log`/`.log(...)` for logging parser progress.

This is a terrible hack, but it sure helps to debug complicated nested
parsers.  I don't even know what a principled approach would look
like; since our parser combinators are so frequently expressed in
code, it's hard to imagine a data-driven interpreter that can help
debug things.

* Part 2: Use `value_and_span` apparatus in tx-parser/.

I break an abstraction boundary by returning a value column
`edn::ValueAndSpan` rather than just an `edn::Value`.  That is, the
transaction processor shouldn't care where the `edn::Value` it is
processing arose -- even we care to track that information we should
bake it into the `Entity` type.  We do this because we need to
dynamically parse the value column to support nested maps, and parsing
requires a full `edn::ValueAndSpan`.  Alternately, we could cheat and
fake the spans when parsing nested maps, but that's potentially
expensive.

* Part 3: Use `value_and_span` apparatus in query-parser/.

* Part 4: Use `value_and_span` apparatus in root crate.

* Review comment: Make Span and SpanPosition Copy.

* Review comment: nits.

* Review comment: Make `or` be `or_exactly`.

I baked the eof checking directly into the parser, rather than using
the skip and eof parsers.  I also took the time to restore some tests
that were mistakenly commented out.

* Review comment: Extract and use def_matches_* macros.

* Review comment: .map() as late as possible.
2017-04-06 10:06:28 -07:00
Emily Toop
8e6f37e709 #260 Convert Schema into edn::Value (#384) r=nalexander, r=rnewman
* Part 1 - Create as_edn_value function.

* Do not include defaults inside output.
* Pretty-printed by default. Do we want to make that a flag?
* Includes simple test just to make sure it works.

* Part 2 - only include ident if available.

* Part 3 - Remove spacing and newlines as unnecessary.

* Update function to build edn::Value directly rather than parsing from string

* Update test to actually test the functionality.

* Address review comments ncalexan.

 * Rename `as_edn_value` to `to_edn_value`.
 * Move `db/src/values.rs` to `core/src/values.rs` so we can reference inside `core/src/ib.rs`.
 * Add `lazy-static` crate to core `Cargo.toml`
 * Expose `values` as a public module from `core`.
 * Update references to values in `db/src/bootstrap.rs` & `db/src/lib.rs`.
 * Add new static vars for `DB_FULLTEXT`, `DB_INDEX` & `DB_IS_COMPONENT`.
 * Use static vars exposed in `values` inside `to_edn_value`.
 * Remove `db/id` as key in attribute output and use `entid` as `db/ident` if no `ident` is found for that `entid`.
 * Update test to match new expected output.

* Add doc comment for function

* Address review comments ncalexan.

* Update function docstring to give clearer description of function.
* Do not all entid at all to output.
* Clean up code fetching ident (make it rustier).

* Address review comments rnewman.

* Extract out to new `to_edn_value` functions code for creating `edn::Value`\'s for `ValueType` and `Attribute`.
* Use `map()` to create schema edn value rather than a loop.

* Address review comments rnewman.

* pass cloned instance of ident to `Attribute::get_edn_value`.
* update `use` import for `edn`.
* remove unnecessary  call when using ident as key on `associate_ident`.

* Fixed bug whereby we didn't differentiate between `db.index/value` and `db.index/identity` when generating `edn::Value`

* Add extra assert at the end to ensure we get the same output when we convert the same schema to edn multiple times

* Move check for type of uniqueness to `match` statement.

* Also use `iter` instead of `into_iter` when iterating schema map.
2017-03-30 11:08:36 +01:00
Nick Alexander
15b4195a6e Schema alteration. Fixes #294 and #295. (#370) r=rnewman
* Pre: Don't retract :db/ident in test.

Datomic (and eventually Mentat) don't allow to retract :db/ident in
this way, so this runs afoul of future work to support mutating
metadata.

* Pre: s/VALUETYPE/VALUE_TYPE/.

This is consistent with the capitalization (which is "valueType") and
the other identifier.

* Pre: Remove some single quotes from error output.

* Part 1: Make materialized views be uniform [e a v value_type_tag].

This looks ahead to a time when we could support arbitrary
user-defined materialized views.  For now, the "idents" materialized
view is those datoms of the form [e :db/ident :namespaced/keyword] and
the "schema" materialized view is those datoms of the form [e a v]
where a is in a particular set of attributes that will become clear in
the following commits.

This change is not backwards compatible, so I'm removing the open
current (really, v2) test.  It'll be re-instated when we get to
https://github.com/mozilla/mentat/issues/194.

* Pre: Map TypedValue::Ref to TypedValue::Keyword in debug output.

* Part 3: Separate `schema_to_mutate` from the `schema` used to interpret.

This is just to keep track of the expected changes during
bootstrapping.  I want bootstrap metadata mutations to flow through
the same code path as metadata mutations during regular transactions;
by differentiating the schema used for interpretation from the schema
that will be updated I expect to be able to apply bootstrap metadata
mutations to an empty schema and have things like materialized views
created (using the regular code paths).

This commit has been re-ordered for conceptual clarity, but it won't
compile because it references the metadata module.  It's possible to
make it compile -- the functionality is there in the schema module --
but it's not worth the rebasing effort until after review (and
possibly not even then, since we'll squash down to a single commit to
land).

* Part 2: Maintain entids separately from idents.

In order to support historical idents, we need to distinguish the
"current" map from entid -> ident from the "complete historical" map
ident -> entid.  This is what Datomic does; in Datomic, an ident is
never retracted (although it can be replaced).  This approach is an
important part of allowing multiple consumers to share a schema
fragment as it migrates forward.

This fixes a limitation of the Clojure implementation, which did not
handle historical idents across knowledge base close and re-open.

The "entids" materialized view is naturally a slice of the "datoms"
table.  The "idents" materialized view is a slice of the
"transactions" table.  I hope that representing in this way, and
casting the problem in this light, might generalize to future
materialized views.

* Pre: Add DiffSet.

* Part 4: Collect mutations to a `Schema`.

I haven't taken your review comment about consuming AttributeBuilder
during each fluent function.  If you read my response and still want
this, I'm happy to do it in review.

* Part 5: Handle :db/ident and :db.{install,alter}/attribute.

This "loops" the committed datoms out of the SQL store and back
through the metadata (schema, but in future also partition map)
processor.  The metadata processor updates the schema and produces a
report of what changed; that report is then used to update the SQL
store.  That update includes:
- the materialized views ("entids", "idents", and "schema");
- if needed, a subset of the datoms themselves (as flags change).

I've left a TODO for handling attribute retraction in the cases that
it makes sense.  I expect that to be straight-forward.

* Review comment: Rename DiffSet to AddRetractAlterSet.

Also adds a little more commentary and a simple test.

* Review comment: Use ToIdent trait.

* Review comment: partially revert "Part 2: Maintain entids separately from idents."

This reverts commit 23a91df9c35e14398f2ddbd1ba25315821e67401.

Following our discussion, this removes the "entids" materialized
view.  The next commit will remove historical idents from the "idents"
materialized view.

* Post: Use custom Either rather than std::result::Result.

This is not necessary, but it was suggested that we might be paying an
overhead creating Err instances while using error_chain.  That seems
not to be the case, but this change shows that we don't actually use
any of the Result helper methods, so there's no reason to overload
Result.  This change might avoid some future confusion, so I'm going
to land it anyway.

Signed-off-by: Nick Alexander <nalexander@mozilla.com>

* Review comment: Don't preserve historical idents.

* Review comment: More prepared statements when updating materialized views.

* Post: Test altering :db/cardinality and :db/unique.

These tests fail due to a Datomic limitation, namely that the marker
flag :db.alter/attribute can only be asserted once for an attribute!
That is, [:db.part/db :db.alter/attribute :attribute] will only be
transacted at most once.  Since older versions of Datomic required the
:db.alter/attribute flag, I can only imagine they either never wrote
:db.alter/attribute to the store, or they handled it specially.  I'll
need to remove the marker flag system from Mentat in order to address
this fundamental limitation.

* Post: Remove some more single quotes from error output.

* Post: Add assert_transact! macro to unwrap safely.

I was finding it very difficult to track unwrapping errors while
making changes, due to an underlying Mac OS X symbolication issue that
makes running tests with RUST_BACKTRACE=1 so slow that they all time
out.

* Post: Don't expect or recognize :db.{install,alter}/attribute.

I had this all working... except we will never see a repeated
`[:db.part/db :db.alter/attribute :attribute]` assertion in the store!
That means my approach would let you alter an attribute at most one
time.  It's not worth hacking around this; it's better to just stop
expecting (and recognizing) the marker flags.  (We have all the data
to distinguish the various cases that we need without the marker
flags.)

This brings Mentat in line with the thrust of newer Datomic versions,
but isn't compatible with Datomic, because (if I understand correctly)
Datomic automatically adds :db.{install,alter}/attribute assertions to
transactions.

I haven't purged the corresponding :db/ident and schema fragments just
yet:
- we might want them back
- we might want them in order to upgrade v1 and v2 databases to the
  new on-disk layout we're fleshing out (v3?).

* Post: Don't make :db/unique :db.unique/* imply :db/index true.

This patch avoids a potential bug with the "schema" materialized view.
If :db/unique :db.unique/value implies :db/index true, then what
happens when you _retract_ :db.unique/value?  I think Datomic defines
this in some way, but I really want the "schema" materialized view to
be a slice of "datoms" and not have these sort of ambiguities and
persistent effects.  Therefore, to ensure that we don't retract a
schema characteristic and accidentally change more than we intended
to, this patch stops having any schema characteristic imply any other
schema characteristic(s).  To achieve that, I added an
Option<Unique::{Value,Identity}> type to Attribute; this helps with
this patch, and also looks ahead to when we allow to retract
:db/unique attributes.

* Post: Allow to retract :db/ident.

* Post: Include more details about invalid schema changes.

The tests use strings, so they hide the chained errors which do in
fact provide more detail.

* Review comment: Fix outdated comment.

* Review comment: s/_SET/_SQL_LIST/.

* Review comment: Use a sub-select for checking cardinality.

This might be faster in practice.

* Review comment: Put `attribute::Unique` into its own namespace.
2017-03-20 13:18:59 -07:00
Nick Alexander
dcd9bcb1ce Extract partial storage abstraction; use error-chain throughout. Fixes #328. r=rnewman (#341)
* Pre: Drop unneeded tx0 from search results.

* Pre: Don't require a schema in some of the DB code.

The idea is to separate the transaction applying code, which is
schema-aware, from the concrete storage code, which is just concerned
with getting bits onto disk.

* Pre: Only reference Schema, not DB, in debug module.

This is part of a larger separation of the volatile PartitionMap,
which is modified every transaction, from the stable Schema, which is
infrequently modified.

* Pre: Fix indentation.

* Extract part of DB to new SchemaTypeChecking trait.

* Extract part of DB to new PartitionMapping trait.

* Pre: Don't expect :db.part/tx partition to advance when tx fails.

This fails right now, because we allocate tx IDs even when we shouldn't.

* Sketch a db interface without DB.

* Add ValueParseError; use error-chain in tx-parser.

This can be simplified when
https://github.com/Marwes/combine/issues/86 makes it to a published
release, but this unblocks us for now.  This converts the `combine`
error type `ParseError<&'a [edn::Value]>` to a type with owned
`Vec<edn::Value>` collections, re-using `edn::Value::Vector` for
making them `Display`.

* Pre: Accept Borrow<Schema> instead of just &Schema in debug module.

This makes it easy to use Rc<Schema> or Arc<Schema> without inserting
&* sigils throughout the code.

* Use error-chain in query-parser.

There are a few things to point out here:

- the fine grained error types have been flattened into one crate-wide
  error type; it's pretty easy to regain the granularity as needed.

- edn::ParseError is automatically lifted to
  mentat_query_parser::errors::Error;

- we use mentat_parser_utils::ValueParser to maintain parsing error
  information from `combine`.

* Patch up top-level.

* Review comment: Only `borrow()` once.
2017-02-24 15:33:48 -08:00
Jordan Santell
6f67f8563b TypedValue::Keyword now wraps a NamespacedKeyword rather than a String. Fixes #203. r=nalexander" (#329) 2017-02-17 14:07:57 -08:00
Jordan Santell
a59f9583ac Store Idents as NamespacedKeywords, rather than Strings. Fixes #291. (#300)
r=ncalexander
2017-02-17 13:55:36 -08:00
Victor Porof
896d7f8f88 Add a span component to edn::Value, r=ncalexan
Signed-off-by: Victor Porof <victor.porof@gmail.com>
2017-02-17 18:31:26 +01:00
Richard Newman
a87e5a3ec7 Move Schema from mentat_db to mentat_core, improve API. (#290)
* Move Schema from mentat_db to mentat_core.
* Define SchemaMap in terms of Entid, not i64.
* Add Schema::{is_attribute,identifies_attribute}.
* Add pointer to #291.
* Don't pass around 64-bit pointers to 64-bit integers.
2017-02-13 19:20:20 -08:00
Jordan Santell
1deed24f42 Remove usage of global imports in db module. Fixes #251. r=nalexander (#253) 2017-02-10 09:09:13 -08:00
Richard Newman
c111d4daff Move TypedValue into mentat_core. r=jsantell,nalexander 2017-02-08 14:20:10 -08:00
Nick Alexander
afafcd64a0 [tx] Start implementing bulk SQL insertion algorithms (#214). r=rnewman,jsantell
* Pre: Add some value conversion tests.

This is follow-up to earlier work.  Turn TypedValue::Keyword into
edn::Value::NamespacedKeyword.  Don't take a reference to
value_type_tag.

* Pre: Add repeat_values.

Requires itertools, so this commit is not stand-alone.

* Pre: Expose the first transaction ID as bootstrap::TX0.

This is handy for testing.

* Pre: Improve debug module.

* Pre: Bump rusqlite version for https://github.com/jgallagher/rusqlite/issues/211.

* Pre: Use itertools.

* Start implementing bulk SQL insertion algorithms. (#214)

This is slightly simpler re-expression of the existing Clojure
implementation.

* Post: Start generic data-driven transaction testing. (#188)

* Review comment: `use ::{SYMBOL}` instead of `use {SYMBOL}`.

* Review comment: Prefer bindings_per_statement to values_per_statement.
2017-02-08 14:04:32 -08:00
Nick Alexander
81af295948 Start installing SQL schema. (#171) r=rnewman
* Start installing the SQLite store and bootstrapping the datom store.

* Review comment: Decomplect V2_IDENTS.

* Review comment: Decomplect V2_PARTS.

* Review comment: Pre: Expose Clojure's merge on Value instances.

* Review comment: Decomplect V2_SYMBOLIC_SCHEMA.

* Review comment: Decomplect V1_STATEMENTS.

* Review comment: Prefer ? to try!.

* Review comment: Fix typos; format; add TODOs.

* Review comment: Assert that Mentat `Schema` is valid upon creation.

* Review comment: Improve conversion to and from SQL values.

This patch factors the fundamental SQL conversion maps
between (rusqlite::Value, value_type_tag) and (edn::Value, ValueType)
through a new Mentat TypedValue.  (A future patch might rename this
fundamental type mentat::Value.)

To make certain conversion functions infallible, I removed
placeholders for :db.type/{instant,uuid,uri}.  (We could panic
instead, but there's no need to do that right now.)

* Review comment: Always uses bundled SQLite in rusqlite.

This avoids (runtime) failures in Travis CI due to old SQLite
versions.  See 432966ac77.

* Review comment: Move semantics in `from_sql_value_pair`.

* Review comment: DB_EXCISE_BEFORE_T instead of ...BEFORET (no underscore).

* Review comment: Move overview notes to the Wiki.
2017-01-25 16:13:56 -08:00